Display device

ABSTRACT

A display device includes: a transmission-type display member having a display area that is sequentially scanned; and an illumination member that is arranged on a rear face of the display member and includes a plurality of illumination units that are arranged so as to be aligned in a direction from one end portion side toward the other end portion side along a direction in which the display area is sequentially scanned. The illumination unit is in a light emitting state over a predetermined light emitting period after sequential scanning of display units formed from a portion of the display area, which corresponds to the illumination unit, is completed, and the illumination units are sequentially scanned from one end portion side to the other end portion side in accordance with the sequential scanning of the display area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/421,422, filed Mar. 15, 2012, which claims priority to JapanesePatent Application JP 2011-098911, filed in the Japan Patent Office onApr. 27, 2011, the entire disclosures of which are hereby incorporatedherein by reference.

FIELD

The present disclosure relates to a display device.

BACKGROUND

A display device is known having a configuration in which switchingbetween a light emitting area and a non-light emitting area issequentially performed by scanning an illumination unit of a directunder type in synchronization with the scanning of a transmission-typedisplay unit such as a liquid crystal display panel, for example, asdisclosed in JP-A-2000-321551. According to such a display device, amoving image blur is decreased in a hold-type driving display panel soas to improve the performance of displaying a moving image.

SUMMARY

In an illumination unit having a configuration in which the boundarybetween a light emitting area and a non-light emitting area is clearlyvisually recognized, a bright line or a dark line is visually recognizednear the boundary according to the scanning of the illumination unit,whereby luminance unevenness occurs in a displayed image. Accordingly,commonly, the illumination unit is design such that light emitted from alight source that corresponds to the light emitting area reaches thenon-light emitting area to some degree. However, since light is alsoemitted from the illumination unit to a display area of a portion forwhich update has not been completed, a phenomenon occurs in which imagesare visually recognized to overlap each other in two consecutive frames,whereby the image separation characteristics are degraded.

It is therefore desirable to provide a display device capable ofalleviating degradation of the image separation characteristics.

An embodiment of the present disclosure is directed to a display deviceincluding: a transmission-type display member having a display area thatis sequentially scanned; and an illumination member that is arranged ona rear face of the display member and includes a plurality ofillumination units that are arranged so as to be aligned in a directionfrom one end portion side toward the other end portion side along adirection in which the display area is sequentially scanned. Theillumination unit is in a light emitting state over a predeterminedlight emitting period after sequential scanning of display units formedfrom a portion of the display area, which corresponds to theillumination unit, is completed, and the illumination units aresequentially scanned from one end portion side to the other end portionside in accordance with the sequential scanning of the display area, anda length of a waiting time from when the sequential scanning of thedisplay unit is completed to when the corresponding illumination unit isin the light emitting state is set to be nonlinearly decreased inaccordance with a sequence of the scanning of the illumination units atleast in an area located on one end portion side.

According to the display device of the embodiment of the presentdisclosure, the length of the waiting time from when the sequentialscanning of the display units is completed to when the correspondingillumination unit is in the light emitting state is set to benonlinearly decreased in accordance with the sequence of the scanning ofthe illumination unit at least in an area located on one end portionside. Accordingly, the degree of light emission of the illuminationmember is decreased even in an area in which the update of the displaypanel is not completed. Therefore, the degradation of the imageseparation characteristics can be decreased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a display device according toa first embodiment when it is virtually divided.

FIG. 2A is a schematic plan view of an illumination member, and FIG. 2Bis a schematic cross-sectional view when the illumination member is cutoff along a line denoted by A-A shown in FIG. 2A.

FIG. 3 is a conceptual diagram of the display device according to thefirst embodiment.

FIG. 4 is a schematic diagram illustrating the scanning of a displaymember.

FIG. 5 is a schematic diagram illustrating the scanning of anillumination member according to a reference example.

FIG. 6 is a schematic graph illustrating the luminance distribution ofan illumination member when a light source corresponding to anillumination unit positioned in the first row emits light.

FIG. 7 is a schematic graph illustrating the luminance distribution ofthe illumination member when a light source corresponding to anillumination unit positioned in the (Q/2)-th row emits light.

FIG. 8 is a schematic graph illustrating the relation between lightemission of a light source corresponding to an illumination unit and theluminance distribution of the illumination member.

FIG. 9 is a schematic graph illustrating the luminance distribution ofthe illumination member that emits light to a display unit at the timeof starting a light emitting period of the illumination unit positionedin the first row.

FIG. 10 is a schematic graph illustrating the luminance distribution ofthe illumination member that emits light to the display unit at the timeof starting a light emitting period of an illumination unit positionedin the Q-th row.

FIG. 11 is a schematic diagram illustrating the scanning of theillumination member according to the first embodiment.

FIG. 12A is a schematic graph illustrating the relation between thescanning of the illumination member according to the reference exampleand a waiting time, and FIG. 12B is a schematic graph illustrating therelation between the scanning of the illumination member according tothe first embodiment and a waiting time.

FIG. 13 is a schematic graph illustrating the luminance distribution ofthe illumination member that emits light to the display unit at the timeof starting a light emitting period of the illumination unit positionedin the first row according to the first embodiment.

FIG. 14 is a schematic diagram illustrating the scanning of anillumination member according to a modified example of the firstembodiment.

FIG. 15 is a conceptual diagram of a display device according to themodified example of the first embodiment.

FIG. 16 is a schematic diagram illustrating the scanning of anillumination member according to a second embodiment.

FIG. 17A is a schematic diagram illustrating a light emitting period ofthe illumination member according to the first embodiment, and FIG. 17Bis a schematic graph illustrating a light emitting period of theillumination member according to the second embodiment.

FIG. 18 is a schematic perspective view of a display device according toa third embodiment when it is virtually divided.

FIG. 19 is a conceptual diagram of the display device according to thethird embodiment.

FIG. 20 is a partial cross-sectional view acquired when an opticalsplitting unit is cut off along a virtual plane parallel to the X-Yplane.

FIG. 21 is a schematic diagram illustrating the conditions to besatisfied for allowing light of a pixel that is transmitted through afirst opening/closing portion to travel toward viewpoints A₁ to A₄located in an observation area.

FIG. 22 is a schematic diagram illustrating light of a pixel that istransmitted through a second opening/closing portion and travels towardviewpoints A₁ to A₄.

FIG. 23 is a schematic diagram illustrating the scanning of theillumination member and the operation of the optical splitting unitaccording to the third embodiment.

DETAILED DESCRIPTION

Hereinafter, display devices according to embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. However, the present disclosure is not limited to theembodiments, and various numeric values or materials represented in theembodiments are examples. In the description presented below, the samereference sign is assigned to the same elements or elements having thesame function, and duplicate description thereof will not be presented.The description will be presented in the following order.

1. Overall Description of Display Device According To Embodiments ofPresent Disclosure

2. First embodiment

3. Second Embodiment

4. Third Embodiment (and Others)

[Overall Description of Display Device According to Embodiments ofPresent Disclosure]

As described above, a display device according to an embodiment of thepresent disclosure includes: a transmission-type display member that hasa display area that is sequentially scanned; and an illumination memberthat is arranged on the rear face of the display member and includes aplurality of illumination units that are arranged so as to be aligned ina direction from one end portion side toward the other end portion sidealong a direction in which the display area is sequentially scanned. Theillumination units are in the light emitting state over a predeterminedlight emitting period after the sequential scanning of display unitsformed from a portion of the display area that corresponds to theillumination unit is completed, and the illumination units aresequentially scanned from one end portion side toward the other endportion side in accordance with the sequential scanning of the displayarea.

As the transmission-type display member that is used in an embodiment ofthe present disclosure, a known display member, for example, called atransmission-type liquid crystal display panel may be used. The displaymember may be either a monochrome display or a color display. In theembodiments to be described later, a transmission-type liquid crystaldisplay panel of an active matrix type is used as the display member.

The liquid crystal display panel, for example, is formed from a frontpanel that includes a transparent common electrode, a rear panel thatincludes a transparent pixel electrode, and a liquid crystal materialarranged between the front panel and the rear panel. Here, the operationmode of the liquid crystal display panel is not particularly limited.For example, the liquid crystal display panel may be configured to bedriven in a so-called TN (Twisted Nematic) mode or may be configured tobe driven in a VA (Vertical Alignment) mode or an IPS (In-PlaneSwitching) mode.

More particularly, the front panel, for example, is configured by asubstrate that is formed from glass, a transparent common electrode (forexample, formed from ITO (Indium Tin Oxide) disposed on the inner faceof the substrate, and a polarizing film disposed on the outer face ofthe substrate. In the case of a color display, a color filter coatedwith an overcoat layer that is formed from an acrylic resin or an epoxyresin is disposed on the inner side of the substrate, and thetransparent common electrode is formed on the overcoat layer. Inaddition, an orientation film is formed on the transparent commonelectrode as is necessary.

On the other hand, the rear panel, for example, is configured by asubstrate that is formed from glass, a switching element formed on theinner face of the substrate, and a pixel electrode (for example, formedfrom ITO) that is controlled to be conductive/non-conductive by theswitching element. In addition, on the outer face of the substrate, apolarizing film is disposed. An orientation film is formed on the wholeface including the pixel electrode as is necessary.

Various members or materials configuring the liquid crystal displaypanel may be configured by known members or materials. As examples ofthe switching element, there are a three-terminal element such as a thinfilm transistor (TFT), and two-terminal elements such as a metalinsulator metal (MIM) element, a varistor element, and a diode. To theswitching element, for example, a scanning line extending in the rowdirection and a signal line extending in the column direction areconnected.

In addition, as a semi-transparent type display member that has bothcharacteristics of the reflection type and the transmission type, forexample, a liquid crystal display panel of a semi-transmission type thathas both a reflection-type display area and a transmission-type displayarea in pixels is known. Such a semi transmission-type display membermay be used. In other words, in the “transmission-type display member”,a “semi transmission-type display member” is included.

When the number of pixels M×N of the display member is denoted by (M,N), as the values of (M, N), particularly, there are VGA (640, 480),S-VGA (800, 600), XGA (1024, 768), APRC (1152, 900), S-XGA (1280, 1024),U-XGA (1600, 1200), HD-TV (1920, 1080), Q-X GA (2048, 1536), (3840,2160), (1920, 1035), (720, 480), (1280, 960), and the like as examplesof some of the resolutions for an image display. However, the presentdisclosure is not limited thereto.

In the display member, a display unit that is formed from a portion ofthe display area that corresponds to the illumination unit is basicallyconfigured to include pixels of predetermined rows aligned in thescanning direction. It is preferable that the numbers of the rows ofpixels of the display units are configured to be the same. However, thepresent disclosure is not limited thereto.

It is preferable that the illumination member is configured to includethree or more illumination units. In addition, it is preferable that aportion of the display area corresponding to at least about 10 to 20rows corresponds to one illumination unit. From the viewpoint ofperforming fine control, it is preferable to increase the number ofillumination units. However, since the scale of a circuit that drivesthe illumination member is increased in accordance with the number ofthe illumination units, the number of the illumination units may beselected based on the specifications or the design of the displaydevice.

As examples of the light source of the illumination unit, there are alight emitting diode (LED), a cold cathode ray-type fluorescent lamp, anelectroluminescence (EL) device, and the like. From the viewpoint of theminiaturization of the light source, among those, it is preferable thatthe light emitting diode is used as the light source. In such a case,white light can be acquired by configuring a red light emitting diode, agreen light emitting diode, and a blue light emitting diode as one set.Alternatively, white light can be acquired by using white light emittingdiode (for example, a light emitting diode that emits white light bycombining an ultraviolet or blue light emitting diode and fluorescentparticles). In addition, in the former case, light emitting diodes thatemit a fourth color, a fifth color, . . . other than red, green, andblue may be further included.

The illumination member may be configured to include an opticalfunctional sheet such as an optical diffusion sheet in addition to theabove-described light source. In such a case, the optical functionalsheet is arranged between the light source and the display member.

As described above, in the display device according to the embodiment ofthe present disclosure, the length of the waiting time until acorresponding illumination unit is in the light emitting state after thesequential scanning of display units is completed is set so as to benonlinearly decreased in accordance with the scanning sequence of theillumination unit in at least one area located on the end portion side.The length of the waiting time may be configured to be nonlinearlydecreased in accordance with the scanning sequence of the illuminationunit in an area located on one end portion side, or the length of thewaiting time may be configured to be nonlinearly decreased in accordancewith the scanning sequence of the illumination unit in an area locatedon the other end portion side. Furthermore, the length of the waitingtime may be configured to be nonlinearly decreased in accordance withthe scanning sequence of the illumination unit in the area located onone end portion side and the area located on the other end portion side.

In the display device according to the embodiment of the presentdisclosure that includes the above-described various preferredconfigurations, a period after the illumination unit located on oneend-portion side is in the light emitting state until the illuminationunit located on the other end portion side is in the light emittingstate may be configured to be shorter than a period from the start ofthe sequential scanning in the display area to the end thereof.

In the display device according to the embodiment of the presentdisclosure that includes the above-described various preferredconfigurations, a configuration may be employed in which the lightemitting period of the illumination unit arranged in the endportion-side area is set to be shorter as the illumination unit iscloser to the end portion side.

In the display device according to the embodiment of the presentdisclosure that includes the above-described various preferredconfigurations, the display device maybe configured so as to furtherinclude an optical splitting unit that is used for splitting an imagedisplayed on the display member into images for a plurality ofviewpoints.

The configuration of the optical splitting unit is not particularlylimited. As the optical splitting unit, a known member such as aparallax barrier or a lens sheet called a lenticular lens may be used.The optical splitting unit may have a fixed configuration or aconfiguration that can be dynamically changed.

For example, a parallax barrier having a fixed configuration may beformed using a known material by using a known method such as acombination of a photolithographic method and an etching method, any ofvarious printing methods including a screen printing method or an inkjet printing method, a plating method including an electroplating methodand an electroless plating method, or a lift-off method. On the otherhand, a parallax barrier having a dynamic configuration, for example,may be configured by a light valve using a liquid crystal material. As alens sheet having a fixed configuration, for example, a known lenticularlens may be used. In addition, as a lens sheet having a dynamicconfiguration, for example, a gradient index lens using a liquid crystalmaterial may be used.

A main control unit that controls the display device may be configuredby various circuits such as a video signal generating section, a datadriver, and a timing controller. A scanning circuit that scans thedisplay member may be configured by using a shift register circuit orthe like, and an illumination member driving circuit that drives theillumination member may be configured by a shift register circuit, alight source driving circuit, and the like. An optical splitting drivingcircuit that drives the optical splitting unit may be configured by ashift register circuit or the like. These can be configured by usingknown circuit elements.

First Embodiment

A first embodiment relates to a display device according to the presentdisclosure.

FIG. 1 is a schematic perspective view of a display device according tothe first embodiment when it is virtually divided. FIG. 2A is aschematic plan view of an illumination member. FIG. 2B is a schematiccross-sectional view when the illumination member is cut off along aline denoted by A-A shown in FIG. 2A.

As illustrated in FIG. 1, the display device 1 according to the firstembodiment includes a transmission-type display member 10 including adisplay area 11 that is sequentially scanned and an illumination member20 that is arranged on the rear face of the display member 10 andincludes a plurality of illumination units 22 that are arranged so as tobe aligned in a direction from one end portion 21A side toward the otherend portion 21B side along a direction in which the display area 11 issequentially scanned.

For convenience of the description, it is assumed that the display area11 of the display member 10 is parallel to the X-Z plane, and the imageobserver side is the +Y direction. In addition, it is assumed that theplanar shapes of a light emitting face 21 that is configured by a groupof illumination units 22 and the display area 11 coincide with eachother, and the planar shapes of the illumination units 22 are the same.

In the display area 11 of the display member 10, a total of M×N pixels12 including M pixels arranged in the row direction (the X direction inthe figure) and N pixels arranged in the column direction (the Zdirection in the figure) are arranged. A pixel 12 positioned in the m-throw (here, m=1, 2, . . . , M) and the n-th column (here, n=1, 2, . . . ,N) is denoted by an (m, n)-th pixel 12 or a pixel 12 _(m, n)). Inaddition, the m-th pixel 12 may be denoted by a pixel 12 _(m). Thenumber of pixels (M, N) of the display member 10, for example, is (1920,1080). This applies the same to display members according to the otherembodiments.

The display member 10 is formed from a liquid crystal display panel ofthe active matrix type. For convenience of the description, the liquidcrystal display panel is assumed to perform a monochrome display.However, it is a merely an example.

The display member 10 is configured by a front panel that is located onthe image observer side, a rear panel that is located on theillumination member 20 side, a liquid crystal material that is arrangedbetween the front panel and the rear panel, and the like. Forconvenience of the description, the display member 10 is illustrated asone panel in FIG. 1.

The illumination member 20 of the so-called direct under type includes aplurality of (Q) illumination units 22. Each illumination unit 22illuminates a display unit 13 that is formed from a portion of thedisplay area that corresponds to the illumination unit 22 from the rearface. A light source that is included in the illumination unit 22 iscontrolled for each illumination unit 22.

As illustrated in FIGS. 2A and 2B, the illumination member 20 includes acasing 24 that includes a bottom face 24A and a side face 24B and lightsources 23 (a red light emitting diode 23R, a green light emitting diode23G, and a blue light emitting diode 23B) that are formed from a set oflight emitting diodes arranged on the bottom face 24A in correspondencewith the illumination units 22. In the example illustrated in FIGS. 2Aand 2B, a set of a plurality of light emitting diodes is arranged in oneillumination unit 22. Thus, white light having high color purity can beacquired as illumination light by mixing red light, green light, andblue light.

As will be described later, the illumination units 22 are sequentiallyscanned. The light source 23 of the scanned illumination unit 22 emitslight, the light is transmitted through an optical functional sheet 25that is formed from an optical diffusion sheet or the like, andirradiates the display unit 13 corresponding to the illumination unit 22from the bottom face.

However, the configuration of the illumination member is not limited tothe above-described configuration but may be configured (so-called anedge light type configuration) to include a light guiding plate that isformed from a transparent material such as acryl and a light sourcearranged on the side face of the light guiding plate.

FIG. 3 is a conceptual diagram of the display device according to thefirst embodiment.

The display device 1 is driven by a main control member 101 to which asignal is input from the outside, a scanning circuit 102 that scans thedisplay member 10, and an illumination member driving circuit 103 thatdrives the illumination member 20. In FIG. 1, circuits including themain control member 101, the scanning circuit 102, and the illuminationmember driving circuit 103 are not illustrated.

An input signal VD corresponding to an image to be displayed is input tothe main control member 101. The main control member 101 generates videosignals VS based on the input signal VD and sequentially applies thevideo signals VS to data lines DTL of the display member 10.

In addition, the main control member 101 generates a clock signal CLK1that is used for controlling the scanning timing of the scanning circuit102 for the display area and a clock signal CLK2 that is used forcontrolling the scanning timing of the illumination member drivingcircuit 103 for the illumination unit 22. The main control member 101,for example, can be configured by known circuits called a logic circuit,a latch circuit, and a shift register circuit. In addition, the scanningcircuit 102, for example, can be configured by using a known circuitsuch as a shift register circuit and the like, and the illuminationmember driving circuit 103 can be configured by using known circuitssuch as a shift register circuit, a light source driving circuit, andthe like.

The scanning circuit 102 sequentially scans the display area 11 bysequentially applying scanning signals to scanning lines SCL. Moreparticularly, in the first embodiment, line sequential scanning isperformed for each line. The direction of the scanning is the Zdirection. The illumination member driving circuit 103 sequentiallyscans the illumination units 22 by sequentially applying control signalsto control lines BCL.

However, the line sequential scanning is not limited to be configured soas to be performed for each line. The display member, for example, maybe configured such that data lines are independently arranged incorrespondence with odd lines and even lines, and line sequentialscanning for two lines is performed once. In other words, the “linesequential scanning” includes a form in which a plurality of lines aresimultaneously scanned in addition to the configuration in whichscanning is performed for each line.

The display area 11 that is configured by the pixels 12 arranged in atwo-dimensional matrix pattern is virtually divided into Q display units13. When this state is represented by a “row” and a “column”, thedisplay unit 13 can be stated to be divided into display units of Q rowsand one column.

Since the planar shapes of the illumination units 22 are the same,basically, the display unit 11 is divided into equal parts. In such acase, the display unit 13 can be stated to be configured by pixels 12 of(N/Q) rows and M columns. For example, when (M, N)=(1920, 1080), andQ=20, the display unit 13 is configured by pixels 12 of 54 rows and 1920columns. In addition, in a case where there is a fraction after thedecimal point in (N/Q), it may be appropriately distributed to thedisplay units.

FIG. 4 is a schematic diagram illustrating the scanning of the displaymember.

The display area 11 is sequentially scanned toward the Z direction.Accordingly, in order to display one frame, first, the pixels 12configuring a display unit 13 ₁ are scanned, and thereafter, pixels 12configuring each display unit 13 are scanned in the order of displayunits 13 ₂, 13 ₃, . . . , 13 _(Q-1), 13 _(Q). In addition, in order tosettle an operation of recording a new video signal into a pixel 12 orthe state of the pixel recording operation after that, a predeterminedperiod is necessary. When this period is represented as a rewritingperiod, and the remaining period is represented as a settling period,the scanning of the display member 10 can be schematically representedas in FIG. 4. In addition, in order to further prompt the settling ofthe pixel state, a configuration may be employed in which the same datais written twice. In such a case, for example, the settling period maybe handled to be started in accordance with the end of the secondrecording operation.

In the first embodiment, based on the operation of the main controlmember 101 and the like, the length of the waiting time after thesequential scanning of the display units 13 is completed until thecorresponding illumination unit 22 is in the light emitting state is setto be nonlinearly decreased in accordance with the scanning sequence ofthe illumination unit 22 at least in an area located on one end portionside. More particularly, the length of the waiting time is set to benonlinearly decreased in accordance with the scanning sequence of theillumination unit 22 in an area located on one end portion side and inan area located on the other end portion side. First, in order to helpthe understanding of the present disclosure, the operation of areference example in which the length of the waiting time is set to beconstant regardless of the scanning sequence of the illumination unit 22and the problems therein will be described.

FIG. 5 is a schematic diagram illustrating the scanning of theillumination member according to a reference example.

In the operation according to the reference example, the length of thewaiting time is set to be constant regardless of the scanning sequenceof the illumination unit 22. For convenience of the description, thelength of the waiting time in the reference example is assumed to be thelength of a time after the scanning of a display unit 13 ends until thesettling period of a display unit 13 that is located below theabove-described display unit 13 by one level. When the waiting time isdenoted by t_(a), and the light emitting period of the illumination unit22 is denoted by t_(b), the scanning of the illumination member 20 canbe schematically represented as in FIG. 5. In addition, a broken lineillustrated in FIG. 5 represents the scanning timing of the displaymember 10 illustrated in FIG. 4.

In a case where the light emitting period of each illumination unit 22is included within the settling period of the corresponding display unit13, theoretically, images of two frames are not visually recognized tooverlap each other. However, light emitted from the light source 23 ofthe illumination unit 22 reaches the other illumination units 22, andaccordingly, images of two frames are visually recognized to overlapeach other. Hereinafter, the description will be presented withreference to FIGS. 6 to 10.

FIG. 6 is a schematic graph illustrating the luminance distribution ofthe illumination member when a light source corresponding to anillumination unit positioned in the first row emits light. FIG. 7 is aschematic graph illustrating the luminance distribution of theillumination member when a light source corresponding to theillumination unit positioned in the (Q/2)-th row emits light. FIG. 8 isa schematic graph illustrating the relation between light emission ofthe illumination unit and the luminance distribution of the illuminationmember.

As illustrated in FIG. 6, when the light source 23 corresponding to theillumination unit 22 ₁ positioned in the first row emits light, theluminance on the face of the illumination unit 22 ₁ is the highest. Inaddition, the light emitted from the light source of the illuminationunit 22 ₁ reaches the illumination units 22 ₂ to 22 _(Q), and theprofile of the luminance is represented as the graph illustrated in FIG.6. The horizontal axis in the graph is in arbitrary units acquired bysetting the highest value of the luminance at the time of light emissionof the light source 23 corresponding to the illumination unit 22 ₁ toone. This applies the same to the other figures.

The profile of the luminance at the time of light emission of the lightsource 23 corresponding to the illumination unit 22 _(Q) positioned inthe Q-th row is a profile acquired by inverting the graph illustrated inFIG. 6.

As illustrated in FIG. 7, when the light source 23 corresponding to theillumination unit 22 _(Q/2) positioned in the (Q/2)-th row emits light,the luminance on the face of the illumination unit 22 _(Q/2) is thehighest. However, since the conditions of the illumination member 20 forthe reflection of light and the like inside the casing 24 change, thehighest luminance is lower than that illustrated in FIG. 6.Qualitatively, the value of the highest luminance decreases further, asthe illumination unit 22 is located closer to the center. The lightemitted from the light source of the illumination unit 22 _(Q/2) reachesthe illumination units 22 ₁ to 22 _(Q/2−1) and the illumination units 22_(Q/2+1) to 22 _(Q), and the profile of the luminance is represented asthe graph illustrated in FIG. 7.

Consequently, the relation between the light emission of the lightsource 23 corresponding to the illumination unit 22 and the luminancedistribution of the illumination member 20 is represented as in FIG. 8.In FIG. 8, while the profile of the luminance of each of theillumination units 22 ₁, 22 ₂, 22 _(Q/2), 22 _(Q/2+1), 22 _(Q−1), and 22_(Q) is illustrated as an example, the profile of the luminance of acertain illumination unit 22 _(q1) that is arranged between theillumination units 22 ₂ and 22 _(Q/2) and the profile of the luminanceof a certain illumination unit 22 _(q2) that is arranged between theillumination units 22 _(Q/2+1) and 22 _(Q) are also illustrated as anexample.

For example, in FIG. 5, the display units 13 ₁ and 13 ₂ are in thesettling period at the time of starting the emission period of theillumination unit 22 ₁. On the other hand, the display units 13 ₃ to 13_(Q) are in the rewriting period. Accordingly, the display units 13 ₃ to13 _(Q) are in the state in which a video signal of the previous frameis written or a state in which a new video signal is in the middle ofbeing rewritten.

FIG. 9 is a schematic graph illustrating the luminance distribution ofthe illumination member that emits light to the display unit at the timeof starting the light emitting period of the illumination unitpositioned in the first row. FIG. 10 is a schematic graph illustratingthe luminance distribution of the illumination member that emits lightto the display unit at the time of starting the light emitting period ofthe illumination unit positioned in the Q-th row.

As illustrated in FIG. 9, also when the light source 23 corresponding tothe illumination unit 22 ₁ emits light, the display units 13 ₃ to 13_(Q) are irradiated with light having intensity to some degrees.Accordingly, in FIG. 9, a portion of the graph that is applied withdiagonal lines represents an image during the rewriting period,therefore, the separation characteristics of the images are degraded.

On the other hand, at the time of staring the light emitting period ofthe illumination unit 22 _(Q) illustrated in FIG. 5, all the displayunits 13 ₁ to 13 _(Q) are in the settling period. Accordingly, asillustrated in FIG. 10, a phenomenon does not occur in which an imageduring the rewriting period is displayed in accordance with lightemitted from the illumination member 20.

As described above, in the operation according to the reference example,a phenomenon occurs in which an image during a rewriting period isdisplayed even though the illumination unit is scanned. According to thefirst embodiment, the degree in which an image during a rewriting periodis displayed can be decreased. Hereinafter, the operation according tothe first embodiment will be described with reference to FIGS. 11 to 13.

FIG. 11 is a schematic diagram illustrating the scanning of theillumination member according to the first embodiment. FIG. 12A is aschematic graph illustrating the relation between the scanning of theillumination member according to the reference example and a waitingtime. FIG. 12B is a schematic graph illustrating the relation betweenthe scanning of the illumination member according to the firstembodiment and a waiting time.

According to the first embodiment, in an area (an upper end portionarea) located on one end portion 21A side and an area (a lower endportion) located on the other end portion 21B side, a waiting timet_(a)′ is set so as to be non-linearly decreased in accordance with thescanning sequence of the illumination unit 22.

In the reference example, as illustrated in FIG. 12A, the length of thewaiting time t_(a) is constant. In contrast to this, according to thefirst embodiment, as illustrated in FIG. 12B, the length of the waitingtime t_(a)′ is set so as to be the largest in the illumination unit 22 ₁positioned in the first row. In addition, in the upper end portion areaand the lower end portion area, the waiting time is set so as to benonlinearly decreased in accordance with the scanning sequence of theillumination unit 22. Here, although the waiting time is constant in theupper end portion area, the lower end portion area, and the centerportion area, the present disclosure is not limited thereto.

As described above, since the waiting time is set to be nonlinearlydecreased, a period from when the illumination unit 22 positioned on oneend portion 21A side is in the light emitting state to when theillumination unit 22 positioned on the other end portion 21B side is inthe light emitting state is shorter than the period from the start tothe end of the sequential scanning in the display area.

FIG. 13 is a schematic graph illustrating the luminance distribution ofthe illumination member that emits light to the display unit at the timeof starting a light emitting period of the illumination unit positionedin the first row according to the first embodiment.

For example, in a case where a time when the light emitting period ofthe illumination unit 22 ₁ positioned in the first row is started isconsidered, in the first embodiment, a state is formed in which thescanning of the display units 13 advances more than that of thereference example. Accordingly, as illustrated in FIG. 13, the degree ofdisplaying an image during the rewriting period is lower than thatillustrated in FIG. 9. This is similar in the other illumination units22 located in the upper end portion area.

By setting as such, the length of the waiting time of the illuminationunit 22 located in the upper end portion area can be securedsufficiently, compared with that of the reference example.

In addition, the waiting time may be configured to be nonlinearlydecreased only in the upper end portion area, or/and the waiting timemay be configured to be nonlinearly decreased only in the lower endportion area.

The image separation characteristics of the display device 1 aresuppressed from being degraded. Accordingly, by alternately displayingan image for the left eye and an image for the right eye in the displaydevice 1, and by switching a so-called glass-type optical shutter inaccordance with the display, a stereoscopic image having excellent imagequality can be displayed.

In addition, in the description presented above, although all the planarshapes of the illumination units are configured to be the same, forexample, a configuration may be employed in which the planar shapes ofthe illumination units arranged at the upper end and the lower end areenlarged. A schematic diagram illustrating the scanning of anillumination member according to a modified example of the firstembodiment is illustrated in FIG. 14. In addition, a conceptual diagramof a display device 1′ according to the modified example of the firstembodiment is illustrated in FIG. 15. In the example illustrated inFIGS. 14 and 15, an illumination member 20′ is used in whichillumination units 22 corresponding to four rows at the upper end andthe lower end are replaced with an illumination unit 22′.

Second Embodiment

A second embodiment is a modified example of the first embodiment. Thesecond embodiment is different from the first embodiment in that thelight emitting period of an illumination unit arranged in an arealocated on the end portion side is set to be shortened as theillumination unit is located closer to the end portion side.

A schematic perspective view of a display device 2 according to thesecond embodiment is similar to that acquired by replacing the displaydevice 1 illustrated in FIG. 1 with the display device 2. In addition, aconceptual diagram of the display device according to the secondembodiment is similar to that acquired by replacing the display device 1illustrated in FIG. 3 with the display device 2 and is similar to thatacquired by replacing the illumination member driving circuit 103 withan illumination member driving circuit 203. The illumination memberdriving circuit 203 drives an illumination unit 22 arranged in an arealocated on the end portion side such that the illumination period isfurther shortened as the illumination unit 22 is located closer to theend portion side.

As illustrated in FIG. 8 that has been referred to in the firstembodiment, the luminance of the illumination member 20 tends to behigher toward an end portion 21A in the area of one end portion 21Aside. Similarly, in the area located on the other end portion 21B side,the luminance tends to be higher toward an end portion 21B in the arealocated on the end portion 21B side. Accordingly, when the illuminationunit 22 is scanned, it is visually recognized that the luminance becomeshigher toward the end portion from the center portion.

Accordingly, in the second embodiment, the illumination member drivingcircuit 203 drives the illumination units 22 arranged in the arealocated on the end portion side such that the light emitting period ofan illumination unit 22 is set to be shortened as the illumination unitis located closer to the end portion side.

FIG. 16 is a schematic diagram illustrating the scanning of theillumination member according to the second embodiment. FIG. 17A is aschematic diagram illustrating the light emitting period of theillumination member according to the first embodiment. FIG. 17B is aschematic graph illustrating the light emitting period of theillumination member according to the second embodiment.

Since the light emitting period of an illumination unit 22 is set to beshorter as the illumination unit 22 is located closer to the end portionside, the value of a waiting time t_(a)″ in the upper end portionillustrated in FIG. 16 can be set to be longer than the waiting timet_(a)′ described in the first embodiment. According to the secondembodiment, the length t_(b)″ of the light emitting period is shortertoward the end portion 21A on the side of the upper end portion and isshortened toward the end portion 21B on the side of the lower endportion area.

As illustrated in FIG. 17A, according to the first embodiment, thelength of the light emitting period t_(b) of the illumination unit 22 isconstant regardless of the scanning sequence. In contrast to this,according to the second embodiment, as illustrated by a curve 1 shown inFIG. 17B, the light emitting period t_(b)″ is shortened toward the endportion.

Accordingly, the trend in which the luminance is visually recognized tobe higher toward the end portion from the center portion is compensated,whereby the uniformity of the luminance in the displayed image can beimproved. In addition, since the value of the waiting time t_(a)″ in theupper end portion area can be set to be longer than that of the firstembodiment, the image separation characteristics can be furtherimproved.

Third Embodiment

A third embodiment is a modified example of the first embodiment. Thereis a difference that an optical splitting unit is further included whichis used for splitting an image displayed on a display unit into imagesof a plurality of viewpoints.

FIG. 18 is a schematic perspective view of a display device according tothe third embodiment when it is virtually divided.

As illustrated in FIG. 18, the display device 3 according to the thirdembodiment includes a transmission-type display member 10 including adisplay area 11 that is sequentially scanned and an illumination member20 that is arranged on the rear face of the display member 10 andincludes a plurality of illumination units 22 that are arranged so as tobe aligned in a direction from one end portion side 21A toward the otherend portion side 21B along a direction in which the display area 11 issequentially scanned. In addition, the optical splitting unit 30 isfurther included which is used for splitting an image displayed on thedisplay member 10 into a plurality of viewpoint images.

The configurations and the operations of the display member 10 and theillumination member 20 are basically similar to those described in thefirst embodiment, and thus the description thereof will not bepresented.

Although the number of viewpoints of the image in the third embodimentwill be described as four viewpoints A₁, A₂, A₃, and A₄ in each one ofobservation areas WA_(L), WA_(C), and WA_(R) illustrated in FIG. 18,this is merely an example. The number of the observation areas and thenumber of viewpoints may be appropriately set based on the design of thedisplay device 3. When a distance between the viewpoints is set to about65 [mm], and a parallax image at each viewpoint is set to be observed,an image observer recognizes the displayed images as a stereoscopicimage.

FIG. 19 is a conceptual diagram of the display device according to thethird embodiment.

An optical splitting unit driving circuit 304 is operated based on aclock signal CLK3 supplied from the main control unit 301 andappropriately changes the states of first opening/closing portion 31,second opening/closing portion 32, and third opening/closing portion 33to be described later. Accordingly, the image displayed on the displaymember 10 is split into images of each viewpoint. The otherconfigurations are similar to those of the first embodiment illustratedin FIG. 3, and thus the description thereof will not be presented.

As illustrated in FIG. 18, the optical splitting unit 30 extends in thevertical direction (the Z direction in the figure) and includes aplurality of the first opening/closing portions 31, the secondopening/closing portions 32, and the third opening/closing portions 33that are arranged so as to be aligned in the horizontal direction (the Xdirection in the figure). The first opening/closing portion 31 and thesecond opening/closing portion 32 are alternately arranged with thethird opening/closing portion 33 interposed therebetween in thehorizontal direction. A barrier forming area 34 is configured by aplurality of the first opening/closing portions 31, the secondopening/closing portions 32, and the third opening/closing portions 33aligned in the horizontal direction. In the third embodiment, P firstopening/closing portions 31 are arranged, and (P−1) secondopening/closing portions 32 are arranged. In the third embodiment, thenumber of the third opening/closing portions 33 is the same as that ofthe second opening/closing portions 32. The p-th (here, p=1, 2, . . . ,P) first opening/closing portion 31 is denoted by 31 _(p). This issimilar for the second opening/closing portions 32. All the firstopening/closing portion 31, the second opening/closing portion 32, andthe third opening/closing portion 33 may be represented as theopening/closing portions 31, 32, and 33. The relation between “P” and“M” will be described later with reference to FIG. 21.

FIG. 20 is a partial cross-sectional view acquired when the opticalsplitting unit is cut off along a virtual plane parallel to the X-Yplane.

In FIG. 20, a reference sign PW represents the width of the firstopening/closing portion 31 or the second opening/closing portion 32 inthe horizontal direction (the X direction in the figure), and areference sign SW represents the width of the third opening/closingportion 33 in the horizontal direction. A pitch between the firstopening/closing portions 31 and 31 adjacent to each other in thehorizontal direction and a pitch between the second opening/closingportions 32 and 32 adjacent to each other in the horizontal directionare the same and are represented by a reference sign RD. A pitch betweenthe first opening/closing portion 31 and the second opening/closingportion 32 in the horizontal direction is RD/2.

The optical splitting unit 30, for example, includes one pair oflight-transmitting substrates 330A and 330B that are formed from glasssubstrates and a liquid crystal material layer 336 arranged between thesubstrates 330A and 330B and includes a plurality of the opening/closingportions 31, 32, and 33 that can be switched between a lighttransmitting state and a light shielding state. The optical splittingunit 30 splits an image displayed on the display member 10 by settingpredetermined opening/closing portions to be in a light transmittingstate and the other opening/closing portions to be in a light shieldingstate.

More particularly, on the liquid crystal material layer 336 side of thesubstrate 330A, a transparent common electrode 334, for example, formedfrom ITO is formed on the whole face, and an orientation film 335A, forexample, formed from polyimide is formed thereon. In addition, on theliquid crystal material layer 336 side of the substrate 330B, a firsttransparent electrode 331, a second transparent electrode 332, and athird transparent electrode 333, which are formed from ITO, for exampleand formed in correspondence with the opening/closing portions 31 and32, and 33, are formed. All the first transparent electrode 331, thesecond transparent electrode 332, and the third transparent electrode333 may be collectively represented as transparent electrodes 331, 332,and 333.

The planar shape of the transparent electrodes 331, 332, and 333 is anapproximate stripe shape. On the substrate 330B including areas on thetransparent electrodes 331, 332, and 333, an orientation film 335B, forexample, formed from polyimide is formed. Furthermore, the transparentcommon electrode 334 and the transparent electrodes 331, 332, and 333may be configured to be replaced with each other.

An orientation process is performed for the face of the firstorientation film 335A that is located on the liquid crystal materiallayer 336 side, for example, in a direction forming 335 degrees withrespect to the X axis on the X-Z plane by using a known method such as arubbing process. On the other hand, an orientation process is performedfor the face of the second orientation film 335B that is located on theliquid crystal material layer 336 side in a direction forming 45 degreeswith respect to the X axis on the X-Z plane.

FIG. 20 illustrates a state in a case where any electric field is notgenerated between the transparent common electrode 334 and thetransparent electrodes 331, 332, and 333. In this state, the direction(also referred to as a “director”) of the molecular axis of liquidcrystal molecules 336A that configure the liquid crystal material layer336 forms about 335 degrees with respect to the X axis on the X-Z planeon the substrate 330A side. Then, the direction of the molecular axisgradually changes and forms about 45 degrees with respect to the X axison the X-Z plane on the substrate 330B side. The liquid crystal materiallayer 336 is operated in a so-called TN (twisted nematic) mode.

For the convenience of the description, the polarizing axis of lightemitted from the display member 10 is assumed to form 45 degrees withrespect to the X axis on the X-Z plane according to a polarizing film,which is not illustrated in the figure, stacked on the surface of thedisplay member 10. On the face of the substrate 330B that is located onthe display member 10 side, a polarizing film 337B is stacked, and, onthe face of the substrate 330A that is located on the observation areaside, a polarizing film 337A is stacked. The polarizing film 337B isstacked such that the polarizing axis forms 45 degrees with respect tothe X axis on the X-Z plane, and the polarizing film 337A is stackedsuch that the polarizing axis forms 335 degrees with respect to the Xaxis on the X-Z plane. The polarizing films 337A and 337B are arrangedto be in a state in which the polarizing axes thereof are perpendicularto each other (cross Nichol). In addition, a polarizing film, which isnot illustrated in the figure, stacked on the surface of the displaymember 10 and the polarizing film 337B may be configured to be commonlyshared.

All the first transparent electrodes 331 are electrically connectedthrough wirings not illustrated in the figure. Similarly, all secondtransparent electrodes 332 are electrically connected through wiringsnot illustrated in the figure, and all third transparent electrodes 333are electrically connected through wirings not illustrated in thefigure.

A constant voltage (for example, 0 volts) is applied to the transparentcommon electrode 334, and independent voltages are applied to the firsttransparent electrode 331, the second transparent electrode 332, thethird transparent electrode 333 based on the operation of the opticalsplitting unit driving circuit 304.

An operation performed in a case where any electric field is notgenerated between the transparent common electrode 334 and thetransparent electrodes 331, 332, and 333, in other words, an operationperformed when voltages having the same value are applied to thetransparent common electrode 334 and the transparent electrodes 331,332, and 333 will be described. In such a case, light incident to theliquid crystal material layer 336 through the polarizing film 337B hasthe polarizing direction to be changed by 90 degrees by the liquidcrystal molecules 336A and is transmitted through the polarizing film337A. Accordingly, the optical splitting unit 30 is operated in aso-called normally-white mode.

In a case where a fixed optical splitting unit is used, as will bedescribed later, “the resolution/the number of viewpoints of the displaymember” is the resolution of a stereoscopic image, and accordingly, theresolution of the stereoscopic image is decreased. According to thethird embodiment, by using a dynamic optical splitting unit, thedecrease in the resolution of the stereoscopic image can be alleviated.

In particular, in order to display one stereoscopic image, two images (afirst field image and a second field image) are displayed on the displaymember 10. Then, based on the operations of the main control unit 301and the optical splitting unit driving circuit 304, only the firstopening/closing portion 31 is configured to be in the light transmittingstate when the first field image is displayed, and only the secondopening/closing portion 32 is configured to be in the light transmittingstate when the second field image is displayed. By forming all theopening/closing portions 31, 32, and 33 to be in the light transmittingstate, an ordinary image can be displayed as well.

FIG. 21 is a schematic diagram illustrating the conditions to besatisfied for allowing light of a pixel that is transmitted through thefirst opening/closing portion to travel toward viewpoints A₁ to A₄located in the observation area.

For convenience of the description, it is assumed that a boundary of the(m+1)-th pixel 12 _(m+1) and the (m+2)-th pixel 12 _(n+2) and a centerpoint between the viewpoints A₂ and A₃ in the observation area WA_(C)are positioned on a virtual straight line that passes through the centerof the first opening/closing portion 31 _(p) and extends in the Ydirection. Here, a pixel pitch is denoted by ND [mm]. In addition, adistance between the display member 10 and the optical splitting unit 30is denoted by Y1 [mm], and a distance between the optical splitting unit30 and the observation areas WA_(L), WA_(C), and WA_(R) is denoted by Y2[mm]. Furthermore, a distance between viewpoints adjacent to each otherin the observation areas WA_(L), WA_(C), and WA_(R) is denoted by DP[mm]. In addition, as described above, the pitch of the firstopening/closing portion 31 in the horizontal direction and the pitch ofthe second opening/closing portion 32 in the horizontal direction aredenoted by RD [mm].

In FIG. 21, the first opening/closing portion 31 is in the lighttransmitting state, and the second opening/closing portion 32 and thethird opening/closing portion 33 are in the light shielding state. Inaddition, in order to clearly represent the light transmitting state andthe light shielding state, diagonal lines are applied to theopening/closing portions that are in the light shielding state. This isapplied similarly to other figures to be described later.

For convenience of the description, it is assumed that the width PW ofthe first opening/closing portion 31 and the second opening/closingportion 32 is sufficiently small, and the description will be presentedwith focusing on the orbit of light passing through the center of thefirst opening/closing portion 31.

While a virtual straight line that passes through the center of thefirst opening/closing portion 31 _(p) and extends in the Y direction isused as a reference, a distance up to the center of the pixel 12 _(m+3)is denoted by X1, a distance up to the viewpoint A₁ of the observationarea WA_(C) located at the center is denoted by X2, and a distance up tothe viewpoint A₁ of the observation area WA_(R) located on the rightside is denoted by X3. When light emitted from the pixel 12 _(m+3) istransmitted through the first opening/closing portion 31 _(p) andtravels toward the viewpoint A₁ of the observation area WA_(C) locatedat the center, based on the geometric similarity relation, the conditionrepresented in the following Equation (1) is satisfied.

Y1:X1=Y2:X2   (1)

Here, X1=1.5×ND and X2=1.5×DP, and accordingly, when these arereflected, Equation (1) is represented as in the following Equation(1′).

Y1:1.5×ND=Y2: 1.5×DP   (1′)

When the above-described Equation (1′) is satisfied, it is geometricallyapparent that light emitted from the pixels 12 _(m+2), 12 _(m−1) and 12_(m) travels toward the viewpoints A₂, A₃, and A₄ of the observationarea WA_(C).

In addition, when light emitted from the pixel 12 _(m+3) is transmittedthrough the first opening/closing portion 31 _(p+1) and travels towardthe viewpoint A₁ of the observation area WA_(R), based on the geometricsimilarity relation, the condition represented in the following Equation(2) is satisfied.

Y1:(RD−X1)=(Y1+Y2):X3−X1   (2)

Here, X1=1.5×ND and X3=2.5×DP, and accordingly, when these arereflected, Equation (2) is represented as in the following Equation(2′).

Y1:(RD−1.5×ND)=(Y1+Y2):(2.5×DP−1.5×ND)   (2′)

When the above-described Equation (2′) is satisfied, it is geometricallyapparent that light emitted from the pixels 12 _(m+2), 12 _(m+1), and 12_(m) travels toward the viewpoints A₂, A₃, and A₄ of the observationarea WA_(R).

In addition, the condition that light emitted from the pixels 12 _(m+3),12 _(m+2), 12 _(m+1), and 12 _(m) passes through the firstopening/closing portion 31 _(p−1) and travels toward the viewpoints A₁,A₂, A₃, and A₄ of the observation area WA_(L) that is located on theleft side is similarly acquired by appropriately reversing thedescription relating to the light that passes through the firstopening/closing portion 31 _(p+1), and thus the description thereof willnot be presented.

The values of the distance Y2 and the distance DP are set topredetermined values based on the specifications of the display device3. In addition, the value of the pixel pitch ND is determined based onthe structure of the display member 10. Based on Equations (1′) and(2′), the following Equations (3) and (4) are acquired for the distanceY1 and the pitch RD.

Y1=Y2×ND/DP   (3)

RD=4×DP×ND/(DP+ND)   (4)

For example, when the pixel pitch ND of the display member 10 is 0.500[mm], the distance Y2 is 1500 [mm], and the distance DP is 65.0 [mm],the distance Y1 is about 11.5 [mm], and the pitch RD is about 1.95 [mm]that is about four times the pixel pitch ND. Accordingly, theabove-described “M” and “P” has the relation of M≈P×4.

As described above, the horizontal resolution of the image for eachviewpoint that is split by the optical splitting unit is decreased toM/4. Thus, in the optical splitting unit, by changing the states of thefirst opening/closing portion 31 and the second opening/closing portion32, a decrease in the horizontal resolution is alleviated.

FIG. 22 is a schematic diagram illustrating light of a pixel that istransmitted through the second opening/closing portion and travelstoward the viewpoints A₁ to A₄.

In FIG. 22, the second opening/closing portion 32 is in the lighttransmitting state, and the first opening/closing portion 31 and thethird opening/closing portion 33 are in the light shielding state.

In such a case, for example, light emitted from pixels 12 _(m+5), 12_(m+4), 12 _(m+3), and 12 _(m−2) is transmitted through the secondopening/closing portion 32 _(p) and travels toward the viewpoints A₁,A₂, A₃, and A₄ of the observation area WA_(C) located at the center.Accordingly, in FIGS. 21 and 22, the pixels facing each view point areshifted by two pixels. Therefore, by combining the state illustrated inFIG. 21 and the state illustrated in FIG. 22, the horizontal resolutionof an image for each viewpoint is M/2.

FIG. 23 is a schematic diagram illustrating the scanning of theillumination member and the operation of the optical splitting unitaccording to the third embodiment.

In the third embodiment, one frame period is configured by a first fieldperiod and a second field period. In the first field period, the firstopening/closing portion 31 of the optical splitting unit 30 is in thelight transmitting state, and the second opening/closing portion 32 andthe third opening/closing portion 33 are in the light shielding state.In addition, in the second field period, the second opening/closingportion 32 of the optical splitting unit 30 is in the light transmittingstate, and the first opening/closing portion 31 and the thirdopening/closing portion 33 are in the light shielding state.

The operations of the display member 10 and the illumination member 20in each field period are similar to the above-described operationsperformed in the frame period in the first embodiment. In the imagedisplayed on the display member 10 in each field period, the imageseparation characteristics are decreased. Accordingly, since the errorin parallax information of an image that is visually recognized at eachviewpoint is decreased, a satisfactory stereoscopic image can bevisually recognized.

As above, although preferred embodiments of the present disclosure havebeen described, the present disclosure is not limited to theembodiments. The configurations and the structures of the displaydevices described in the embodiments are examples and can beappropriately changed.

In the third embodiment, although the opening/closing portion of theoptical splitting unit is formed in the shape of a row extending in thevertical direction, for example, a configuration may be employed inwhich the opening/closing portion obliquely extends so as to form anangle with respect to the vertical direction. In such a case, byarranging pin-hole shaped opening/closing portions so as to be obliquelyconnected to each other, a configuration may be employed in which theopening/closing portions obliquely extending on the whole areconfigured.

In addition, the technology of the present disclosure may be implementedas the following configurations.

(1) A display device including: a transmission-type display memberhaving a display area that is sequentially scanned; and an illuminationmember that is arranged on a rear face of the display member andincludes a plurality of illumination units that are arranged so as to bealigned in a direction from one end portion side toward the other endportion side along a direction in which the display area is sequentiallyscanned. The illumination unit is in a light emitting state over apredetermined light emitting period after sequential scanning of displayunits formed from a portion of the display area, which corresponds tothe illumination unit, is completed, and the illumination units aresequentially scanned from one end portion side to the other end portionside in accordance with the sequential scanning of the display area, anda length of a waiting time from when the sequential scanning of thedisplay unit is completed to when the corresponding illumination unit isin the light emitting state is set to be nonlinearly decreased inaccordance with a sequence of the scanning of the illumination units atleast in an area located on one end portion side.

(2) The display device described in (1), wherein the length of thewaiting time is set to be nonlinearly decreased in accordance with thesequence of the scanning of the illumination units in an area located onthe one end portion side and an area located on the other end portionside.

(3) The display device described in (1) or (2), wherein a period fromwhen the illumination unit located on one end portion side is in thelight emitting state to when the illumination unit located on the otherend portion side is in the light emitting state is shorter than a periodfrom the start to the end of the sequential scanning for the displayarea.

(4) The display device described in any one of (1) to (3), wherein thelight emitting period of the illumination unit arranged in an arealocated on the end portion side is set to be shorter as the illuminationunit is closer to the end portion side.

(5) The display device described in any one of (1) to (4), wherein theillumination member includes three or more of the illumination units.

(6) The display device described in any one of (1) to (5), wherein thedisplay member is formed from a liquid crystal display panel.

(7) The display device described in any one of (1) to (6), wherein anoptical splitting unit that is used for splitting an image displayed onthe display member into images for a plurality of viewpoints is furtherincluded.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A display device comprising: a display memberthat includes a plurality of display units; and an illumination memberthat includes a plurality of illumination units arranged on a rear faceof the display member, wherein an illumination unit included in theplurality of illumination units is in a light emitting state afterbeginning of scanning of the display unit corresponding to theillumination unit, and wherein a length of a time from when the scanningof the display units is started to when the corresponding illuminationunit is in the light emitting state is nonlinearly decreased inaccordance with a sequence of the scanning of the illumination units atleast in an area located on one end portion side.
 2. The display deviceaccording to claim 1, wherein the length of time is set to benonlinearly decreased in accordance with the sequence of the scanning ofthe illumination units in the area located on the one end portion sideand an area located on another end portion side.
 3. The display deviceaccording to claim 1, wherein a period from when an illumination unitincluded in the illumination unit that is located on one end portionside is in the light emitting state to when an illumination unitincluded in the illumination unit that is located on the other endportion side is in the light emitting state is shorter than a periodfrom the start to the end of the sequential scanning for the displayarea.
 4. The display device according to claim 1, wherein a lightemitting period of the illumination unit arranged in an area located onthe end portion side is set to be shorter as the illumination unit iscloser to the end portion side.
 5. The display device according to claim1, wherein the illumination member includes three or more of theillumination units.
 6. The display device according to claim 1, whereinthe display member is formed from a liquid crystal display panel.
 7. Thedisplay device according to claim 1, further comprising an opticalsplitting unit that is used for splitting an image displayed on thedisplay member into images for a plurality of viewpoints.
 8. A displaydevice comprising: a display member that includes a plurality of displayunits; and an illumination member that includes a plurality ofillumination units arranged on a rear face of the display member,wherein a period from when an illumination unit located on one endportion side is in the light emitting state to when an illumination unitlocated on another end portion side is in the light emitting state isshorter than a period from the start to the end of the sequentialscanning for the display area, and wherein a length of a time from whenthe scanning of the display units is started to when a correspondingillumination unit is in the light emitting state is nonlinearlydecreased at least in an area located on one end portion side.
 9. Thedisplay device according to claim 8, wherein the length of the time isset to be nonlinearly decreased in accordance with the sequence of thescanning of the illumination units in an area located on the one endportion side and an area located on the other end portion side.
 10. Thedisplay device according to claim 8, wherein a light emitting period ofthe illumination unit arranged in an area located on the end portionside is set to be shorter as the illumination unit is closer to the endportion side.
 11. The display device according to claim 8, wherein theillumination member includes three or more of the illumination units.12. The display device according to claim 8, wherein the display memberis formed from a liquid crystal display panel.
 13. The display deviceaccording to claim 8, further comprising an optical splitting unit thatis used for splitting an image displayed on the display member intoimages for a plurality of viewpoints.
 14. A display device comprising: adisplay member that includes a plurality of display units; and anillumination member that includes a plurality of illumination unitsarranged on a rear face of the display member, wherein a period fromwhen an illumination unit located on one end portion side is in thelight emitting state to when an illumination unit located on the otherend portion side is in the light emitting state is shorter than a periodfrom the start to the end of the sequential scanning for the displayarea, and wherein a light emitting period of the illumination unitlocated on the end portion side is shorter than the light emittingperiod of the illumination unit located on a middle portion.
 15. Thedisplay device according to claim 14, wherein the length of the time isset to be nonlinearly decreased in accordance with the sequence of thescanning of the illumination units in an area located on the one endportion side and an area located on the other end portion side.
 16. Thedisplay device according to claim 14, wherein the illumination memberincludes three or more of the illumination units.
 17. The display deviceaccording to claim 14, wherein the display member is formed from aliquid crystal display panel.
 18. The display device according to claim14, further comprising an optical splitting unit that is used forsplitting an image displayed on the display member into images for aplurality of viewpoints.
 19. An illumination device comprising aplurality of illumination units, wherein a horizontal scan frequency ofthe illumination device is set unevenly, and wherein a light emittingperiod of an illumination unit located on one end portion side isshorter than a light emitting period of an illumination unit located ona middle portion.
 20. The illumination device according to claim 19,wherein the illumination device has a direct-under type structure. 21.The illumination device according to claim 19, wherein the illuminationdevice has an edge-light type structure.